Process for preparing polyols

ABSTRACT

The present invention relates to a process for preparing polyols. In particular, the present invention relates to the preparation, in a single step, of polyols by a process involving a hydrohydroxymethylation reaction starting from a composition A comprising one or more compounds of formula (I).

FIELD OF THE INVENTION

The invention relates to a process for preparing polyols, preferablystarting from triglycerides. In particular, the invention relates to aprocess for preparing polyols, in a single step, by reductivehydroformylation or hydrohydroxymethylation reaction.

TECHNICAL BACKGROUND OF THE INVENTION

Polyols are generally produced from petroleum. Polyols are used in manyfields of application, such as textiles, plastics, chemistry, themanufacturing industry or the cosmetics industry. Polyols are inparticular used in the preparation of coatings, of adhesives, ofelastomers, of resins or of foams.

Polyols are generally prepared via an alkene hydroformylation reaction.However, most of the processes described in the prior art regarding thistype of approach use ligands that are difficult to handle in the openair, such as trialkylphosphines or phosphites which degrade in water. Asimpler alternative consists in using amines as ligands. The use oftertiary amines has been described in the literature for convertingterminal alkenes to alcohols by means of a reductive hydroformylationreaction (Morales Torres et al., Catal. Sci. Technol., 2015, 5, 34-54).Various systematic studies have shown the influence of amine, in termsof structure, of basicity and of amount, on the hydroformylationreaction with rhodium (Hunter et al., Appl. Catal., 1985, 19, 275-285).The most recent use of this type of catalytic system dates back to 2012by Alper et al., (Adv. Synth. Catal., 2012, 354, 2019-2022) on thesynthesis of terminal alcohols from styrene in the presence of tertiarydiamines as ligand. The production of alcohol by this process usingrhodium-amine catalytic systems has also been described in EP 0014225and U.S. Pat. No. 4,197,414, but only starting from light olefins of1-hexene type.

For heavier olefins, polyols are preferentially synthesized by anepoxidation reaction as described by WO 2006/012344.

SUMMARY OF THE INVENTION

The present invention allows the preparation of polyols from biobasedcompounds, for example from a vegetable oil. The process is particularlyadvantageous for the selective preparation of polyols from triglycerideswith a high yield and high selectivity.

The present invention relates to a process for preparing polyols from acomposition A comprising one or more compounds of formula (I)

wherein

-   -   R¹, R², R³, R⁴, R⁵, R⁶ and R⁷ are, independently of one another,        and for R³ and R⁷ independently for each of the n units, chosen        from the group consisting of H, —OR¹⁵, C₁-C₁₀ alkyl which is        unsubstituted or substituted with one or more —OR¹⁵ groups,        C₆-C₁₂ aryl which is unsubstituted or substituted with one or        more —OR¹⁵ groups, or C₃-C₁₀ cycloalkyl which is unsubstituted        or substituted with one or more —OR¹⁵ groups, or a group of        formula (Ia)

-   -   R¹⁵ represents H or C₁-C₁₀ alkyl which is unsubstituted or        substituted with one or more —OH groups;    -   a, b, x and y are independently of one another, independently        for each group of formula (Ia), independently for each        [(CH₂)_(a)—C═C—(CH₂)_(b)]_(r) unit and independently for each        [(CH₂)_(x)—C═C—(CH₂)_(y)]_(p) unit, an integer between 0 and 20,        advantageously between 0 and 15, preferably between 0 and 12;    -   r is an integer between 1 and 10, advantageously between 1 and        5;    -   p is an integer between 1 and 10, advantageously between 1 and        5;    -   n is an integer between 1 and 7;    -   said process comprising a step a) of placing together, with        stirring and under an atmosphere of hydrogen and of carbon        monoxide:        -   at least one precatalyst which is a complex comprising a            transition metal chosen from column 9 of the periodic table            of elements,        -   a tertiary amine, or a non-quaternary ammonium salt thereof,            of formula NR⁸R⁹R¹⁰ wherein R⁸, R⁹ and R¹⁰ represent,            independently of one another, a C₁-C₁₀ alkyl, a C₆-C₁₂ aryl            or a C₃-C₁₀ cycloalkyl, or R⁸ and R⁹ form, together with the            nitrogen atom to which they are attached, a heterocycle            comprising four, five or six ring members, and        -   said composition A comprising one or more compounds of            formula (I).

The present process allows the formation of one or more compoundsderived from said one or more compounds of formula (I) wherein, for allor some of the carbon-carbon double bonds, a carbon atom of thecarbon-carbon double bonds of the compound of formula (I) has beensubstituted with a —CH₂OH group, the other carbon atom with this samecarbon double bond being substituted with a hydrogen.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 represents a scheme of the synthesis of polyols according to oneparticular embodiment of the invention.

FIG. 2 represents a ¹H NMR spectrum of triolein.

FIG. 3 represents a ¹H NMR spectrum of the product obtained by means ofthe process according to one particular embodiment, starting fromtriolein.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

The term “substituted” as used in the present invention means that oneor more hydrogen atoms of the group to which the term “substitute”refers is replaced with one of the substituents named, provided that thenormal valency of the atom on which the substitution is considered isnot exceeded and that the substitution results in a stable chemicalcompound, that is to say a compound that is sufficiently robust to beisolated from a reaction mixture.

The term “alkyl” refers to linear or branched hydrocarbon-based chainscontaining the specified number of carbon atoms. For example, C₁-C₆alkyl means a linear or branched alkyl group containing at least 1 andat most 6 carbon atoms. The alkyl group can be substituted with anunsubstituted aryl group, halogen, NO₂, CN, SO₃H, OH, C₁-C₁₀ alkoxy, ora carbonyl or carboxyl group. The term “aryl” refers to an aromatichydrocarbon-based ring containing the specified number of carbon atomswhich is unsubstituted or substituted with an unsubstituted C₁-C₁₀alkyl, halogen, NO₂, CN, SO₃H, or a carbonyl, carboxyl, OH or C₁-C₁₀alkoxy group. For example aryl can be a phenyl, naphthyl, anthracyl orphenanthryl. The term “cycloalkyl” refers to a fused monocyclic orpolycyclic, non-aromatic hydrocarbon-based ring comprising the specifiednumber of carbon atoms. For example, cycloalkyl comprises cyclopropyl,cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl or cyclooctyl. The term“heterocycle” refers to a fused monocyclic or polycyclic, non-aromatichydrocarbon-based ring comprising the specified number of ring members,wherein at least one of the carbon atoms is replaced with a phosphorus,sulfur, nitrogen or oxygen atom. In particular, the term heterocycle asused in the present invention refers to a fused monocyclic orpolycyclic, non-aromatic hydrocarbon-based ring comprising the specifiednumber of ring members and wherein at least one of the carbon atoms isreplaced with a nitrogen atom.

According to the present invention, a process for preparing polyols isprovided. The present process for preparing polyols is carried outstarting from a composition A comprising one or more compounds offormula (I)

wherein

-   -   R¹, R², R³, R⁴, R⁵, R⁶ and R⁷ are, independently of one another,        and for R³ and R⁷ independently for each of the [CR³R⁷]_(n)        units, chosen from the group consisting of H, —OR¹⁵, C₁-C₁₀        alkyl which is unsubstituted or substituted with one or more        —OR¹⁵ groups, C₆-C₁₂ aryl which is unsubstituted or substituted        with one or more —OR¹⁵ groups, or C₃-C₁₀ cycloalkyl which is        unsubstituted or substituted with one or more —OR¹⁵ groups, or a        group of formula (Ia)

-   -   R¹⁵ represents H or C₁-C₁₀ alkyl which is unsubstituted or        substituted with one or more —OH groups;    -   a, b, x and y are, independently of one another, independently        for each group of formula (Ia), independently for each        [(CH₂)_(a)—C═C—(CH₂)_(b)]_(r) unit and independently for each        [(CH₂)_(x)—C═C—(CH₂)_(y)]_(p) unit, an integer between 0 and 20,        advantageously between 0 and 15, preferably between 0 and 12;    -   r is an integer between 1 and 10, advantageously between 1 and        5;    -   p is an integer between 1 and 10, advantageously between 1 and        5;    -   n is an integer between 1 and 7;    -   said process comprising a step a) of placing together, with        stirring and under an atmosphere of hydrogen and of carbon        monoxide:        -   at least one precatalyst which is a complex comprising a            transition metal chosen from column 9 of the periodic table            of elements,        -   a tertiary amine, or a non-quaternary ammonium salt thereof,            of formula NR⁸R⁹R¹⁰ wherein R⁸, R⁹ and R¹⁰ represent,            independently of one another, a C₁-C₁₀ alkyl, a C₆-C₁₂ aryl            or a C₃-C₁₀ cycloalkyl, or R⁸ and R⁹ form, together with the            nitrogen atom to which they are attached, a heterocycle            comprising four, five or six ring members,        -   said composition A comprising one or more compounds of            formula (I).

The carbon-carbon double bonds contained in the compound(s) of theformula (I), (Ia) or (II) as described in the present invention can bein the cis or trans configuration. The term “carbon-carbon doublebond(s)” encompasses both configurations.

FIG. 1 illustrates the process according to one particular embodiment ofthe present invention involving a hydrohydroxymethylation reaction. Thecompound (I) is represented by triolein comprising three carbon-carbondouble bonds. The process according to the present invention thus allowsthe preparation of a polyol wherein the three carbon-carbon double bondsare hydrohydroxymethylated. The —CH₂OH group can be borne, for each ofthe carbon-carbon double bonds, by any one of the carbon atoms C1 or C2,C′1 or C′2, or C″1 or C″2.

According to one preferred embodiment, said composition A can compriseat least 20% by weight of said one or more compounds of formula (I) onthe basis of the total weight of the composition A, advantageously atleast 30% by weight, preferably at least 40% by weight, morepreferentially at least 50% by weight, in particular at least 60% byweight, more particularly at least 70% by weight, preferably at least80% by weight.

Preferably, a and x can be, independently of one another, independentlyfor each group of formula (Ia), independently for each[(CH₂)_(a)—C═C—(CH₂)_(b)]_(r) unit and independently for each[(CH₂)_(x)—C═C—(CH₂)_(y)]_(p) unit, an integer between 1 and 12,advantageously between 2 and 10, preferably between 3 and 9, inparticular between 3 and 8 and more particularly between 4 and 8.

Preferably, b and y can be, independently of one another, independentlyfor each group of formula (Ia), independently for each[(CH₂)_(a)—C═C—(CH₂)_(b)]_(r) unit and independently for each[(CH₂)_(x)—C═C—(CH₂)_(y)]_(p) unit, an integer between 0 and 12,advantageously between 0 and 10, preferably between 0 and 9, inparticular between 2 and 9, and more particularly between 3 and 8.

Preferably, n can be an integer between 1 and 7, advantageously between1 and 5, preferably between 1 and 4, in particular between 1 and 3, andmore particularly n is 1.

Preferably, p can be an integer between 1 and 5, advantageously between1 and 4, preferably between 1 and 3. In particular, p is 1, 2 or 3, moreparticularly p is 1 or 2.

Preferably, r can be an integer between 1 and 5, advantageously between1 and 4, preferably between 1 and 3. In particular, r is 1, 2 or 3, moreparticularly r is 1 or 2.

Advantageously, in said one or more compounds of formula (I), at leastone of the substituents R¹, R², R³, R⁴, R⁵, R⁶ and R⁷ is a group offormula (Ia). Preferably, in said one or more compounds of formula (I),at least two of the substituents R¹, R², R³, R⁴, R⁵, R⁶ and R⁷ are agroup of formula (Ia).

According to one preferred embodiment, said one or more compounds offormula (I) are of formula (II)

wherein

-   -   a, b, x and y are, independently of one another, independently        for each group of formula (Ia), independently for each        [(CH₂)_(a)—C═C—(CH₂)_(b)]_(r) unit and independently for each        [(CH₂)_(x)—C═C—(CH₂)_(y)]_(p) unit, an integer between 0 and 20,        advantageously between 0 and 15, preferably between 0 and 12;    -   r is an integer between 1 and 10, advantageously between 1 and        5;    -   p is an integer between 1 and 10, advantageously between 1 and        5;    -   n is an integer between 1 and 7, preferably between 1 and 4;    -   R¹, R², R³, R⁴ and R⁵ are, independently of one another, and for        R³ independently for each of the n units, chosen from the group        consisting of H, —OR¹⁵, a group of formula (Ia) as described        above, C₁-C₁₀ alkyl which is unsubstituted or substituted with        one or more —OR¹⁵ groups, C₆-C₁₂ aryl which is unsubstituted or        substituted with one or more —OR¹⁵ groups, or C₃-C₁₀ cycloalkyl        which is unsubstituted or substituted with one or more —OR¹⁵        groups, wherein R¹⁵ represents H or C₁-C₁₀ alkyl which is        unsubstituted or substituted with one or more —OH groups.

In said one or more compounds of formula (II), a and x can be,independently of one another, independently for each[(CH₂)_(x)—C═C—(CH₂)_(y)]_(p) unit and independently for each[(CH₂)_(a)—C═C—(CH₂)_(b)]_(r) unit, an integer between 1 and 12,advantageously between 2 and 10, preferably between 3 and 9, inparticular between 3 and 8 and more particularly between 4 and 8.

In said one or more compounds of formula (II), b and y can be,independently of one another, independently for each[(CH₂)_(x)—C═C—(CH₂)_(y)]_(p) unit and independently for each[(CH₂)_(a)—C═C—(CH₂)_(b)]_(r) unit, an integer between 0 and 12,advantageously between 0 and 10, preferably between 0 and 9, inparticular between 2 and 9, and more particularly between 3 and 8.

In said one or more compounds of formula (II), n can be an integerbetween 1 and 7, advantageously between 1 and 5, preferably between 1and 4, in particular between 1 and 3, and more particularly n is 1.

In said one or more compounds of formula (II), p can be an integerbetween 1 and 5, advantageously between 1 and 4, preferably between 1and 3. In particular, p is 1, 2 or 3, more particularly p is 1 or 2.

In said one or more compounds of formula (II), r can be an integerbetween 1 and 5, advantageously between 1 and 4, preferably between 1and 3. In particular, r is 1, 2 or 3, more particularly r is 1 or 2.

Preferably, in said one or more compounds of formula (II), thesubstituents R¹, R², R³, R⁴ and R⁵ can be, independently of one another,and for R³ independently for each of the n units, chosen from the groupconsisting of H, —OR¹⁵, a group of formula (Ia) as described above,C₁-C₁₀ alkyl which is unsubstituted or substituted with one or more—OR¹⁵ groups, wherein R¹⁵ represents H or C₁-C₁₀ alkyl which isunsubstituted or substituted with one or more —OH groups.

In particular, in said one or more compounds of formula (II), thesubstituents R¹, R², R³, R⁴ and R⁵ can be, independently of one another,and for R³ independently for each of the n units, chosen from the groupconsisting of H, and C₁-C₁₀ alkyl which is unsubstituted or substitutedwith one or more —OR¹⁵ groups, wherein R¹⁵ represents H.

More particularly, in said one or more compounds of formula (II), thesubstituents R¹, R², R³, R⁴ and R⁵ are a hydrogen.

Thus, according to one preferred embodiment, said one or more compoundsare of formula (II) wherein

-   -   a and x can be, independently of one another, independently for        each [(CH₂)_(x)—C═C—(CH₂)_(y)]_(p) unit and independently for        each [(CH₂)_(a)—C═C—(CH₂)_(b)]_(r) unit, an integer between 1        and 12, advantageously between 2 and 10, preferably between 3        and 9, in particular between 3 and 8 and more particularly        between 4 and 8;    -   b and y can be, independently of one another, independently for        each [(CH₂)_(x)—C═C—(CH₂)_(y)]_(p) unit and independently for        each [(CH₂)_(a)—C═C—(CH₂)_(b)]_(r) unit,    -   an integer between 0 and 12, advantageously between 0 and 10,        preferably between 0 and 9, in particular between 2 and 9, and        more particularly between 3 and 8;    -   R¹, R², R³, R⁴ and R⁵ are a hydrogen;    -   p is 1, 2 or 3 independently for each        [(CH₂)_(x)—C═C—(CH₂)_(y)]_(p) unit;    -   r is 1, 2 or 3 independently for each        [(CH₂)_(a)—C═C—(CH₂)_(b)]_(r) unit;    -   n is 1.

According to one particular embodiment of the present invention, saidcomposition A can consist of one or more compounds of formula (I) or(II).

In the process according to the present invention, the tertiary aminecan be of formula NR⁸R⁹R¹⁰ wherein R⁸, R⁹ and R¹⁰ represent,independently of one another, a C₁-C₁₀ alkyl, or R⁸ and R⁹ form,together with the nitrogen atom to which they are attached, aheterocycle comprising four, five or six ring members. Advantageously,the tertiary amine can be of formula NR⁸R⁹R¹⁰ wherein R⁸, R⁹ and R¹⁰represent, independently of one another, a C₁-C₁₀ alkyl, or R⁸ andR⁹form, together with the nitrogen atom to which they are attached, aheterocycle chosen from the group consisting of azetidine, diazetidine,pyrrolidine, imidazolidine, pyrazolidine, piperidine and piperazine. Theimidazolidine and pyrazolidine heterocycles comprise two nitrogen atoms.In the case of the present invention, the two nitrogen atoms of theseimidazolidine and pyrazolidine heterocycles are tertiary. Preferably,the tertiary amine can be of formula NR⁸R⁹R¹⁰ wherein R⁸, R⁹ and R¹⁰represent, independently of one another, C₁-C₁₀ alkyl, or R⁸ and R⁹form, together with the nitrogen atom to which they are attached, apyrrolidine or a piperidine. In particular, the tertiary amine can be offormula NR⁸R⁹R¹⁰ wherein R⁸, R⁹ and R¹⁰ represent, independently of oneanother, a C₁-C₆ alkyl.

The tertiary amine can be supported on a resin. Thus, the substituentR¹⁰ can be a spacer group between the nitrogen atom of the tertiaryamine and the resin. R¹⁰ can be a C₁-C₁₀ alkyl, a benzyl, a C₆-C₁₈ arylor a C₃-C₁₀ cycloalkyl.

Preferably, said tertiary amine has a pKa greater than 6, advantageouslygreater than 7, preferably greater than 8, in particular greater than 9.Preferably, said tertiary amine has a pKa less than 15, advantageouslyless than 14, preferably less than 12, in particular less than 11. Saidtertiary amine can thus have a pKa between 6 and 14, advantageouslybetween 8 and 12, preferably between 9 and 11.

The present process is carried out under pressure of a hydrogen andcarbon monoxide atmosphere. The pressure refers to the sum of thepartial carbon monoxide and hydrogen pressures. The pressure can bebetween 50 bar and 200 bar, advantageously between 65 bar and 150 bar,preferably between 70 bar and 130 bar, in particular between 75 bar and120 bar.

Preferably, the molar ratio between the carbon monoxide and the hydrogencan be between 2:1 and 1:10, advantageously the molar ratio between thecarbon monoxide and the hydrogen is between 1:1 and 1:5, preferably themolar ratio is between 1:1 and 1:3, in particular the molar ratiobetween the carbon monoxide and the hydrogen is between 1:1 and 1:2.

Preferably, step a) of the present process can be carried out at atemperature between 60° C. and 200° C., advantageously between 70° C.and 180° C., preferably between 80° C. and 150° C.

Step a) of the present process can be carried out in the presence of anorganic solvent such as aromatic or aliphatic hydrocarbons. For example,the solvent can be toluene, benzene, hexane or heptane.

As mentioned above, the process according to the present invention iscarried out in the presence of at least one precatalyst. Saidprecatalyst is a complex comprising a transition metal chosen fromcolumn 9 of the periodic table of elements. Advantageously, saidprecatalyst is a complex comprising a transition metal chosen fromcobalt or rhodium. Advantageously, the precatalyst is a complexcomprising rhodium as transition metal and one or more ligands.Preferably, at least one of said one or more ligands is chosen from CO,acetylacetonate, cyclooctadiene, norbornene and acetate.

The precatalyst can be supported on a solid support. The support can becarbon black, SiO₂, Al₂O₃, TiO₂, MgO, ZnO, CaCO₃, CaSO₄ or MgSO₄ or acombination thereof. The weight ratio between the support and theprecatalyst can be between 1 and 100.

Preferably, the molar ratio between the tertiary amine of formulaNR⁸R⁹R¹⁰ as described above and the transition metal of the complex usedas precatalyst in step a) of the present process is greater than 20,advantageously greater than 50, preferably greater than 100, inparticular greater than 200.

Said one or more ligands can also comprise at least one monodentate orbidentate phosphorus-bearing ligand comprising at least one C₆-C₁₈ arylsubstituent substituted in the ortho position with respect to thephosphorus atom or comprising at least one C₆-C₁₈ aryloxy substituent.Advantageously, said phosphorus-bearing ligand can be of formula P(Ar)₃or (Ar)₂'P-L-P(Ar)₂ of which Ar is a C₆-C₁₈ aryl group substituted atleast in the ortho position with respect to the phosphorus atom with agroup selected from the group consisting of C₁-C₆ alkyl, phenyl, benzyl,C₃-C₆ cycloalkyl, halogen, C₁-C₆ alkoxyl and C₆ aryloxy; and L is aspacer arm selected from the group consisting of C₁-C₆ alkyl, C₆-C₁₂aryl and C₃-C₁₀ cycloalkyl. The expression “substituted in the orthoposition with respect to the phosphorus atom” means that, in the arylring, at least one of the two ortho positions with respect to the carbonatom bonded to the phosphorus atom is substituted with one of the groupsmentioned. Preferably, said phosphorus-bearing ligand can be of formulaP(Ar)₃ wherein Ar is a C₆-C₁₈ aryl group substituted in the orthoposition with respect to the phosphorus atom with a group selected fromthe group consisting of methyl, ethyl, methoxy, phenyl, benzyl, —F andcyclohexyl.

Alternatively, said phosphorus-bearing ligand can be of formula P(O—Ar)₃or (Ar—O)₂—P-L-P(O—Ar)₂ wherein Ar is a C₆-C₁₈ aryl group which isunsubstituted or substituted with a group selected from the groupconsisting of C₁-C₆ alkyl, C₃-C₆ alkyl, halogen, C₁-C₆ alkoxyl and C₆aryloxy; and L is a spacer arm selected from the group consisting ofC₁-C₆ alkyl, C₆-C₁₂ aryl and C₃-C₁₀ cycloalkyl. Preferably, saidphosphorus-bearing ligand can be of formula P(O—Ar)₃ wherein Ar is a C₆aryl which is unsubstituted or substituted with a methyl, ethyl,methoxy, phenyl, benzyl or cyclohexyl group.

In particular, said phosphorus-bearing ligand can be P(OPh)₃, P(C₆F₅)₃,P(o-MePh)₃, P(o-OMePh)₃.

Alternatively, said one or more ligands also comprise at least onewater-soluble monodentate or bidentate phosphorus-bearing ligandcomprising at least one functional group SO₃ ⁻X⁺, NR₃ ⁺A⁻, CO₂ ⁻X⁺, Xrepresenting Li, Na or K; and A representing Cl, Br or I.Advantageously, said phosphorus-bearing ligand can be of formula P(Ar)₃or (Ar)₂—P-L-P(Ar)₂ wherein L is a spacer arm selected from the groupconsisting of C₁-C₆ alkyl, C₆-C₁₂ aryl and C₃-C₁₀ cycloalkyl; and Ar isa C₆-C₁₈ aryl which is substituted with at least one functional groupSO₃ ⁻X⁺, NR₃ ⁺A⁻, CO₂ ⁻X⁺, X representing Li, Na or K, and Arepresenting Cl, Br or I; and optionally substituted with a groupselected from the group consisting of C₁-C₆ alkyl, phenyl, benzyl, C₃-C₆cycloalkyl, halogen, C₁-C₆ alkoxyl and C₆ aryloxy.

According to one particular embodiment, step a) also places together amethylated α-, β-, γ-cyclodextrin having an average degree ofsubstitution of between 0.5 and 2.0 or a hydroxylated α-, β-,γ-cyclodextrin having an average degree of substitution of between 0.5and 0.9. Said methylated α-, β-, γ-cyclodextrin can have an averagedegree of substitution of between 1.6 and 2.0, or of between 0.9 and 1.6or of between 0.5 and 0.9. When a cyclodextrin and a water-solublephosphorus-bearing ligand as mentioned above are used in step a), wateris also added in this same step a) in order to create a two-phase mediumcomprising an organic phase and an aqueous phase. Before the reaction iscarried out, the organic phase consists in particular of the compound offormula (I) or (II) according to the present invention and tertiaryamine. In this embodiment, the tertiary amine is of formula NR⁸R⁹R¹⁰wherein R⁸, R⁹ and R¹⁰ represent, independently of one another, a C₄-C₁₀alkyl. When the process is carried out in the presence of acyclodextrin, the precatalyst comprises at least one water-solublemonodentate or bidentate phosphorus-bearing ligand as defined above. Inaddition, the process is carried out under operating conditions whichallow the establishment of an emulsion during the stirring and decantingof the reaction products after the stirring has been stopped, preferablydecanting of at least one part of the compound according to the presentinvention. Advantageously, the proportion of cyclodextrin is between 15%and 40% by weight on the basis of the total weight of water, ofcyclodextrin and of said one or more compounds of formula (I),preferably of formula (II), as described above, placed together in stepa).

The process according to the present invention can also comprise arecycling step when the process is carried out in a two-phase medium.The recycling step comprises degassing the reactor in which the processaccording to the present invention is carried out, removing the organicphase under a controlled atmosphere, and adding to the reactor thecomposition A comprising one or more compounds of formula (I) or offormula (II) as described above, tertiary amine NR⁸R⁹R¹⁰ and optionallyone or more ligands as described above. During this recycling step, thetemperature can remain constant, that is to say remain at thetemperature at which the hydrohydroxymethylation reaction was carriedout, or can be at a temperature above or below the temperature at whichthe hydrohydroxymethylation reaction was carried out.

According to one particular embodiment of the present invention, saidcomposition A comprising one or more compounds of formula (I),preferably comprising one or more compounds of formula (II), is avegetable oil having an average number of unsaturations of between 0.5and 20, advantageously between 0.5 and 15, preferably between 0.5 and10.

Preferably, said composition A comprising one or more compounds offormula (I), preferably of formula (II), is a vegetable oil having anaverage number of unsaturations of less than 3.5, advantageously lessthan 3.4, preferably less than 3.3, more preferentially less than 3.2,in particular less than 3.1, more particularly less than 3.0.Preferably, said vegetable oil has an average number of unsaturations ofgreater than 0.5, advantageously greater than 1, preferably greater than1.5, more preferentially greater than 2.0, in particular greater than2.5. Said vegetable oil can thus have an average number of unsaturationsof between 2.0 and 3.2, advantageously between 2.4 and 3.1, preferablybetween 2.5 and 3.0, in particular between 2.6 and 2.8.

Alternatively, said composition A comprising one or more compounds offormula (I), preferably of formula (II), is a vegetable oil having anaverage number of unsaturations of between 4 and 10.

Methods Determination of the Average Number of Unsaturations

The average number of unsaturations is determined by ¹H NMR indeuterated chloroform (CDCl₃). The NMR analyses are carried out on aBruker 300 MHz instrument. The average number of unsaturations of acompound is calculated from the value of integration of the ¹H NMRsignal of the olefin protons located on the fatty acid unit(s) of thecompound. The ¹H NMR signal of the olefin protons is at 5.3 ppm. If thesignal of the olefin protons is covered by one or more other protons, astandardization factor is applied in order to deduce the contribution ofthe latter proton(s) to the integration value and thus to obtain anintegration value corresponding only to the olefin protons.

In the case of the compounds of formula (II) wherein R³ is a hydrogen inany one of the n units, the ¹H NMR signal of this hydrogen atom coversthe signal of the olefin protons. A standardization factor, denoted FN,is thus calculated according to the equation:

FN=(value of the integration of a signal/theoretical number of protonsof the corresponding signal)

For example, for the case of triglycerides, the standardization factoris calculated from the value of integration of the ¹H NMR signalcorresponding to the protons of the two CH₂ groups of glycerol accordingto the equation FN=B/4. FIG. 2 represents the ¹H NMR spectrum oftriolein. The signal B representative of the signal corresponding to theprotons of the two CH₂ groups of the glycerol unit has the value of 4and the standardization factor is thus 1. The glycerol CH proton coversthe signal of the olefin protons. The average number of unsaturations isthus deduced from the following equation:

DBi=(A−FN)/2

where A corresponds to the value of integration of the signalcorresponding to the CH proton of glycerol and the olefin protons (asindicated in FIG. 2), and FN is the standardization factor describedabove.

When the compound analyzed is not a triglyceride, those skilled in theart will adjust the calculation of the standardization factor FN on thebasis of another proton or of another proton group, for example theprotons located in position C or D in FIG. 2.

Conversion of the Reaction

The conversion of the reaction is given by the following formula:

Conv. (%)=((DBi−DBf)/DBi)×100=((Ai−Af)/(Ai−FN))×100

where DBi and DBf are, respectively, the number of initial and finalunsaturations and Ai and Af are the integration of the signals A at thebeginning and end of the reaction. The signals A correspond to the ¹HNMR signals of the olefin protons, as explained above. If the signal ofthe olefin protons is covered by one or more other protons notcorresponding to the olefin protons, a standardization factor FN isapplied and calculated as explained above.

Determination of the Alcohol Selectivity

The selectivities with respect to aldehydes, alcohols and C═C that arehydrogenated, supported by the products resulting from the reaction, aredetermined by integration of the ¹H NMR signals. FIG. 3 represents a ¹HNMR spectrum of the product resulting from carrying out the processaccording to the invention starting from triolein. The signal of the CH₂protons of the hydroxymethylated group (denoted C in FIG. 3) is at 3.54ppm. The alcohol selectivity of the reaction is given by the formula:

Selec. (HHM) (%)=((C/(2×FN))/(DBi−DBf))×100

where C represents the value of integration of the signal correspondingto the CH₂ protons of the hydroxymethylated group, FN represents thestandardization factor, and DBi and DBf represent the number of initialand final double bonds.

EXAMPLES Example 1

1 ml of triolein (1 mmol), 5 ml of toluene, 3.9 mg of Rh(CO)₂(acac)(0.015 mmol) and 3 mmol of amine are mixed in a reactor. The reaction iscarried out under a pressure of 80 bar of carbon monoxide and hydrogen(molar ratio 1:1) for 18 hours at 80° C.

Table 1 below reports the results obtained with various tertiary amines.

TABLE 1 Catalytic performances as a function of the tertiary amineAldehyde Alcohol Hydrogenation Conversion selec. selec. selec. No. Amine(%) (%) (%) (%) 1 N(Et)₃ 100 0 93 7 2 N(Bu)₃ 100 0 96 4 3 N(Hex)₃ 100 095 5 4 N—Me 100 0 95 5 pyrrolidine 5 TMEDA 100 8 82 9 6 NMP 100 85 0 157 N—Me 100 75 0 25 Pyrrole 8 Pyridine 100 78 0 22 9 1,10-phen 100 76 024 Reaction conditions: triolein: 1 mmol (1 ml, 3 mmol of C═C);Rh(CO)₂(acac): 0.015 mmol (3.9 mg); toluene: 5 ml; amine: 3 mmol (TMEDAand 1,10-phen: 1.5 mmol); CO/H₂ (1:1) pressure: 80 bar; temperature: 80°C.; 18 hours TMEDA: N,N,N′,N′-tetramethylethylenediamine; NMP:N-methyl-2-pyrrolidone; 1,10-phen: 1,10-phenanthroline

The results of example 1 demonstrate that the use of tertiary amineallows the “one pot” synthesis of polyols without the use of aco-catalyst or other additives, under relatively mild catalyticconditions. The use of cyclic or non-cyclic aliphatic tertiary aminesallows the predominant formation of the desired polyols with anexcellent conversion and selectivity. However, the use of nitrogenatedheteroaryls (pyridine and pyrrole) or of amides leads to ahydroformylation reaction without a hydrogenation step, thus givingpredominantly aldehydes.

Example 2

Example 1 was reproduced using tributylamine as tertiary amine and byvarying the carbon monoxide and hydrogen pressure. The reaction time is6 hours. Table 2 reproduces the results obtained.

TABLE 2 Catalytic performances as a function of the syngas pressureAldehyde Alcohol Hydrogenation Conversion selec. selec. selec. No.Pressure (%) (%) (%) (%) 10 80 91 39 53 8 11 100 100 20 75 5 Reactionconditions: triolein: 1 mmol (1 ml, 3 mmol of C═C); Rh(CO)₂(acac): 0.015mmol (3.9 mg); toluene: 5 ml; tributylamine: 3 mmol; CO/H₂ (1:1);temperature: 80° C.; 6 hours

The total CO/H₂ syngas pressure has an influence on thehydrohydroxymethylation conversions and also on the final-productselectivities. When the total pressure increases, the conversion and thealcohol selectivity also increase. It should also be noted that, themore the pressure increases, the more the C═C hydrogenation selectivitydecreases. However, if the pressure is substantially increased, thefirst hydroformylation step is promoted, followed by the step ofhydrogenation of newly formed aldehydes, the hydrogenation of thesubstrate then having to be slower.

Example 3

Example 1 was reproduced in the presence of tributylamine for 6 hourswhile varying the reaction temperature. Table 3 reproduces the resultsobtained.

TABLE 3 Catalytic performances as a function of the temperature AldehydeAlcohol Hydrogenation Temperature Conversion selec. selec. selec. No. (°C.) (%) (%) (%) (%) 12 80 91 39 53 8 13 110 99 2 89 9 14 140 100 0 93 7Reaction conditions: triolein: 1 mmol (1 ml, 3 mmol of C═C);Rh(CO)₂(acac): 0.015 mmol (3.9 mg); toluene: 5 ml; tributylamine: 3mmol; CO/H₂ (1:1) pressure: 80 bar; 6 hours

Above 80° C., the triglyceride conversion increases, accompanied by astrong activity of hydrogenation of the aldehydes produced andsurprisingly limiting the hydrogenation of the carbon-carbon doublebonds of the substrate.

Example 4

Example 4 aims to determine the influence of the CO/H₂ molar ratio onthe hydrohydroxymethylation reaction. Example 1 was reproduced withtriethylamine as tertiary amine. The reaction time was established at 6hours. The results are reproduced in table 4 below.

TABLE 4 Influence of the CO/H₂ ratio Hydro- Con- Aldehyde Alcoholgenation CO/H₂ version selec. selec. selec. No. ratio Amine (%) (%) (%)(%) 15 1:1 N(Et)₃ 94 12 81 7 16 1:2 N(Et)₃ 95 1 93 6 Reactionconditions: triolein: 1 mmol (1 ml, 3 mmol of C═C); Rh(CO)₂(acac): 0.015mmol (3.9 mg); toluene: 5 ml; amine: 3 mmol; total CO/H₂ pressure: 80bar; temperature: 80° C.; 6 hours

Increasing the hydrogen partial pressure has a surprising effect on thealcohol formation. The use of a 1:2 molar ratio of CO/H₂ makes itpossible to reach stoichiometric reaction proportions (one molecule ofCO used for two molecules of hydrogen) and makes the catalytic systemmore hydrogenating so as to rapidly achieve the expected polyols.

Example 5

The present process for preparing polyols was applied starting from anatural vegetable oil. Table 5 reproduces the results obtained.

TABLE 5 Application to vegetable oils Average Hydro- Iso- number ofAldehyde Alcohol genation merization Conv. unsatura- selec. selec.selec. selec. No. Oils (%) tions (%) (%) (%) (%) 17 Olive 94 2.78 2 90 80 Reaction conditions: oil: 1 mmol (1 ml); Rh(CO)₂(acac): 0.015 mmol(3.9 mg); toluene: 5 ml; triethylamine: 3 mmol; CO/H₂ (1:1) pressure: 80bar; temperature: 80° C.

It emerges from these results that the process according to theinvention applies to vegetable oils, that is to say to compositionscomprising triglycerides of different structures.

Example 6

Example 1 was reproduced in the presence of a self-emulsifying system.The addition of cyclodextrin, and in particular of CRYSMEB® (CDsmethylated in position 2 and having a degree of substitution perglucosidic unit (DS) of 0.8) makes it possible to form a surfactantcomplex at the oil/water interface. This interface-stabilizing complexmakes it possible to emulsify the two-phase system and to increase theinterface between the two media. The process is carried out in thepresence of a precatalyst also comprising a water-soluble phosphine-typeligand such as the trisodium salt of triphenylphosphine trisulfonated inthe meta position (TPPTS). The results are reproduced in table 6 below.

TABLE 6 Process in self-emulsifying medium Aldehyde AlcoholHydrogenation Conversion selec. selec. selec. No. Amine (%) (%) (%) (%)18 N(Bu)₃ 92 3 92 4 19 N(Oct)₃ 94 3 91 5 Reaction conditions: triolein:1 mmol (1 ml, 3 mmol of C═C); Rh(CO)₂(acac): 0.015 mmol (3.9 mg); TPPTS:0.075 mmol (42 mg); water: 8 ml; CRYSMEB: 2 mmol (2.3 g); amine: 3 mmol;CO/H₂ (1:1) pressure: 80 bar; temperature: 80° C.; 18 hours.

The use of cyclodextrin in a self-emulsifying medium makes it possibleto efficiently convert the initial C═C unsaturations into alcoholfunction, this being with very good selectivity and while limiting theformation of hydrogenation product.

The terms and descriptions used herein are proposed by way ofillustration only and do not constitute limitations. Those skilled inthe art will recognize that many variations are possible within thespirit and scope of the invention as described in the claims whichfollow, and their equivalents; in said claims, all the terms should beunderstood in their broadest sense unless otherwise indicated.

1. A process for preparing polyols from a composition A, saidcomposition A comprising one or more compounds of formula (I)

wherein R¹, R², R³, R⁴, R⁵, R⁶ and R⁷ are, independently of one another,and for R³ and R⁷ independently for each of the n units, selected fromthe group consisting of H, —OR¹⁵, C₁-C₁₀ alkyl which is unsubstituted orsubstituted with one or more —OR¹⁵ groups, C₆-C₁₂ aryl which isunsubstituted or substituted with one or more —OR¹⁵ groups, or C₃-C₁₀cycloalkyl which is unsubstituted or substituted with one or more —OR¹⁵groups, and a group of formula (Ia)

R¹⁵ represents H or C₁-C₁₀ alkyl which is unsubstituted or substitutedwith one or more —OH groups; a, b, x and y are independently of oneanother, independently for each group of formula (Ia), independently foreach [(CH₂)_(a)—C═C—(CH₂)_(b)]_(r) unit and independently for each[(CH₂)_(x)—C═C—(CH₂)_(y)]_(p) unit, an integer between 0 and 20 r is aninteger between 1 and 10; p is an integer between 1 and 10; n is aninteger between 1 and 7; said process comprising a step a) of placingtogether, with stirring and under an atmosphere of hydrogen and ofcarbon monoxide: at least one precatalyst which is a complex comprisinga transition metal chosen from column 9 of the periodic table, atertiary amine, or a non-quaternary ammonium salt thereof, of formulaNR⁸R⁹R¹⁰ wherein R⁸, R⁹ and R¹⁰ represent, independently of one another,a C₁-C₁₀ alkyl, a C₆-C₁₂ aryl or a C₃-C₁₀ cycloalkyl, or R⁸ and R⁹ form,together with the nitrogen atom to which they are attached, aheterocycle comprising four, five or six ring members, said compositionA comprising said compound of formula (I).
 2. The process as claimed inclaim 1, characterized in that step a) is carried out at a temperaturebetween 70° C. and 180° C., preferably between 80° C. and 150° C.
 3. Theprocess as claimed in claim 1, characterized in that said at least onecompound of formula (I) is of formula (II)

wherein a, b, x and y are, independently of one another, independentlyfor each group of formula (Ia), independently for each[(CH₂)_(a)—C═C—(CH₂)_(b)]_(r) unit and independently for each[(CH₂)_(x)—C═C—(CH₂)_(y)]_(p) unit, an integer between 0 and 20 p is,independently for each [(CH₂)_(x)—C═C—(CH₂)_(y)]_(p) unit, an integerbetween 1 and 5; r is, independently for each[(CH₂)_(a)—C═C—(CH₂)_(b)]_(r) unit, an integer between 1 and 5; R¹, R²,R³, R⁴ and R⁵ are, independently of one another, and for R³independently for each of the n units, selected from the groupconsisting of H, —OR¹⁵, C₁-C₁₀ alkyl which is unsubstituted orsubstituted with one or more —OR¹⁵ groups, and a group of formula (Ia)as described above, R¹⁵ represents H or C₁-C₁₀ alkyl which isunsubstituted or substituted with one or more —OH groups; n is aninteger between 1 and
 4. 4. The process as claimed in claim 3,characterized in that said at least one compound of formula (I) is offormula (II) wherein a and x can be, independently of one another,independently for each [(CH₂)_(x)—C═C—(CH₂)_(y)]_(p) unit andindependently for each [(CH₂)_(a)—C═C—(CH₂)_(b)]_(r) unit, an integerbetween 1 and 12; b and y can be, independently of one another,independently for each [(CH₂)_(x)—C═C—(CH₂)_(y)]_(p) unit andindependently for each [(CH₂)_(a)—C═C—(CH₂)_(b)]_(r) unit, an integerbetween 0 and 12; R¹, R², R³, R⁴ and R⁵ are a hydrogen; p is 1, 2 or 3independently for each [(CH₂)_(x)—C═C—(CH₂)_(y)]_(p) unit; r is 1, 2 or3 independently for each [(CH₂)_(a)—C═C—(CH₂)_(b)]_(r) unit; n is
 1. 5.The process as claimed in claim 1, characterized in that the tertiaryamine is of formula NR⁸R⁹R¹⁰ wherein R⁸, R⁹ and R¹⁰ represent,independently of one another, a C₁-C₁₀ alkyl, or R⁸ and R⁹ form,together with the nitrogen atom to which they are attached, anazetidine, diazetidine, pyrrolidine, imidazolidine or pyrazolidineheterocycle.
 6. The process as claimed in claim 1, characterized in thatthe precatalyst is a complex comprising rhodium as transition metal andone or more ligands.
 7. The process as claimed in claim 1, characterizedin that it is carried out under pressure of a hydrogen and carbonmonoxide atmosphere, said pressure being between 50 bar and 200 bar,advantageously between 65 bar and 150 bar, preferably between 70 bar and130 bar, in particular between 75 bar and 120 bar.
 8. The process asclaimed in claim 1, characterized in that the molar ratio between thecarbon monoxide and the hydrogen is between 2:1 and 1:10.
 9. The processas claimed in claim 1, characterized in that the molar ratio between theamine and the transition metal is greater than
 20. 10. The process asclaimed in claim 1, characterized in that said composition A comprisingone or more compounds of formula (I) is a vegetable oil having anaverage unsaturation number of less than 3.5.
 11. The process as claimedin claim 1, characterized in that a, b, x and y are independently of oneanother, independently for each group of formula (Ia), independently foreach [(CH₂)_(a)—C═C—(CH₂)_(b)]_(r) unit and independently for each[(CH₂)_(x)—C═C—(CH₂)_(y)]_(p) unit, are between 0 and
 15. 12. Theprocess as claimed in claim 1, characterized in that r is between 1 and10 inclusive.
 13. The process as claimed in claim 1, characterized inthat p is between 1 and 10 inclusive.
 14. The process as claimed inclaim 1, characterized in that r is between 1 and 10 inclusive.
 15. Theprocess as claimed in claim 5, characterized in that R⁸, R⁹ and R¹⁰represent, independently of one another, C₁-C₁₀ alkyl, or R⁸ and R⁹form, together with the nitrogen atom to which they are attached, apyrrolidine.
 16. The process as claimed in claim 6, characterized inthat the at least one of said one or more ligands is at least one of CO,acetylacetonate, cyclooctadiene, norbornene or acetate.
 17. The processas claimed in claim 8, characterized in that the molar ratio between thecarbon monoxide and the hydrogen is between 1:1 and 1:5.
 18. The processas claimed in claim 9, characterized in that the molar ratio between theamine and the transition metal is greater than
 50. 19. The process asclaimed in claim 10, characterized in that the average unsaturationnumber of less than 3.4.